From patchwork Thu Jan 12 17:24:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 13098501 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 73F7CC54EBE for ; Thu, 12 Jan 2023 17:27:54 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pG1KV-0007Ha-Ud; Thu, 12 Jan 2023 12:25:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pG1KT-0007HK-Up for qemu-devel@nongnu.org; Thu, 12 Jan 2023 12:25:29 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pG1KR-0008VS-47 for qemu-devel@nongnu.org; Thu, 12 Jan 2023 12:25:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673544326; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lTtatn89Waf5av3fH7wUp46vSF647elQrXj1zIupcQU=; b=QouXaXj2VDPrGpu3WyBP2mYyuV6ZQqUsIMqVezXLs2Crty0bATDycph3Z3ciH3VR8xRgXq uviIqIlwmCX0D9HeHmO2ZxzppeXhefHjh+dPMJfmH+zHd1pYoJEQNDp57Rsm3uHgTn5wXG WJJFkXrqwYl272w4/YP6pghO1YYmXDE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-620-sqwm21ebMr6Tiq-5YITsdQ-1; Thu, 12 Jan 2023 12:25:22 -0500 X-MC-Unique: sqwm21ebMr6Tiq-5YITsdQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 963F33C42204; Thu, 12 Jan 2023 17:25:21 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7654C4078906; Thu, 12 Jan 2023 17:25:18 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: si-wei.liu@oracle.com, Liuxiangdong , Zhu Lingshan , "Gonglei (Arei)" , alvaro.karsz@solid-run.com, Shannon Nelson , Laurent Vivier , Harpreet Singh Anand , Gautam Dawar , Stefano Garzarella , Cornelia Huck , Cindy Lu , Eli Cohen , Paolo Bonzini , "Michael S. Tsirkin" , Jason Wang , Stefan Hajnoczi , Parav Pandit Subject: [RFC v2 12/13] vdpa: preemptive kick at enable Date: Thu, 12 Jan 2023 18:24:33 +0100 Message-Id: <20230112172434.760850-13-eperezma@redhat.com> In-Reply-To: <20230112172434.760850-1-eperezma@redhat.com> References: <20230112172434.760850-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Spuriously kick the destination device's queue so it knows in case there are new descriptors. RFC: This is somehow a gray area. The guest may have placed descriptors in a virtqueue but not kicked it, so it might be surprised if the device starts processing it. However, that information is not in the migration stream and it should be an edge case anyhow, being resilient to parallel notifications from the guest. Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-vdpa.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 40b7e8706a..dff94355dd 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -732,11 +732,16 @@ static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, int ready) } trace_vhost_vdpa_set_vring_ready(dev); for (i = 0; i < dev->nvqs; ++i) { + VirtQueue *vq; struct vhost_vring_state state = { .index = dev->vq_index + i, .num = 1, }; vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state); + + /* Preemptive kick */ + vq = virtio_get_queue(dev->vdev, dev->vq_index + i); + event_notifier_set(virtio_queue_get_host_notifier(vq)); } return 0; }